Localization of Function

Broca’s Area (red spot) was first described in 1861 by Paul Broca, a French physician and anthropologist.

Scientists used to rely on chance opportunities to map brain function. Most studies were on patients with brain lesions that had altered their cognitive abilities and/or behavior.

The first brain region to be “mapped” was the primary speech center in the left hemisphere, known as Broca’s Area, after Dr. Paul Broca. Broca had patients who couldn’t speak. And upon examining these people’s brains after they died, he was able to establish that lesions in a specific brain region had stolen their ability to talk.

But patients with small lesions in one specific brain region are rare. Moreover, a lesion in one brain area can alter activities in distant brain neighborhoods, causing behavioral and cognitive changes that appear entirely unrelated to the lesion. “Brain mapping” has been difficult.

With fMRI and other new brain scanning techniques, however, our understanding of the mind is now exploding.